Explanation :
Beside applying the rule of thirds, the house is now at the crossing zone of three composition lines :
- the horizon
- an ideal slanted line (suggested by the rock edge on the bottom left part ) leading from the bottom left to the house
- the shoreline starting from the bottom right corner.
That tree is a real luck : it helps balancing the composition.

BTW, I have played a little bit with burn brush tool on cloudes, waves and stones to enhance depth ( and drama )